springBoot部署jar、war

maven插件：
<build>
   <plugins>
     <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
   </plugins>
</build>

java -jar xxx.jar
错误信息：no main manifest attribute, in xxx.jar

example.jar
                     |
                     +-META-INF
                     |  +-MANIFEST.MF
                     +-org
                     |  +-springframework
                     |     +-boot
                     |        +-loader
                     |           +-<spring boot loader classes>
                     +-BOOT-INF
                        +-classes
                        |  +-mycompany
                        |     +-project
                        |        +-YourClasses.class
                        +-lib
                           +-dependency1.jar
                           +-dependency2.jar
https://docs.spring.io/spring-boot/docs/2.1.0.BUILD-SNAPSHOT/reference/htmlsingle/#executable-jar-jar-file-structure

// 进行初始化
public class WebApplication extends SpringBootServletInitializer {

                @Override
                protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
                    return application.sources(WebApplication.class);
                }

                public static void main(String[] args) throws Exception {
                    SpringApplication.run(WebApplication.class, args);
                }

            }